Monosulphonated di-ortho-hydroxy-azo dyestuffs



MONOSULPHONATED DI-ORTHO-HYDROXY-AZO DYESTUFFS Rene Eugene Marcel Gangneux, Rouen, France, assignor to Compagnie Francaise des Matieres Colorantes, Paris, France, a French body corporate No Drawing. Filed Jan. 3, 1957, Ser. No. 632,273

Claims priority, application France Jan. 4, 1956 1 Claim. (Cl. 260-195) The present invention concerns improvements in and relating to monosulphonated di-ortho-hydroxy-azo dyestuifs.

The product resulting from the coupling of the diazo compound of 1-amino-2-naphthol-4-sulphonic acid with fl-naphthol has been known for many years and may be considered as one of the more important among the chromium dyestulfs at present used for the production of black shades. The difliculties inititally encountered in the diazotisation of 1-amino-2-naphthol-4-sulphonic acid led those who first prepared this dyestutr to use special methods of diazotisation or of preparation of the dyestutf itself.

German Patents Nos. 156,440, 157,325 and 160,536 used as the diazotisable base l-amino-naphthalene-2z4- disulphonic acid, the diazo compound of which is converted into the diazo derivative of l-amino-Z-naphthol- 4-sulphonic acid by a simple treatment, by reason of the lability of the sulphonic group in the 2 position. In German Patent No. 181,714, 1-amino-2-naphthol-4-sulphonic acid is acetylated, the 1-amino-2-acetoxy-naphthalene-4-sulphonic acid is diazotised, and the dyestuif obtained after coupling with S-naphthol is saponified.

In both cases relatively complicated processes for the preparation of a simple dyestufi are concerned.

German Patents Nos. 171,024 and 175,593 have revealed the possibility of preparaing the diazo-oxide of 1- ited States Patent the di-alkyl metal salts.

paratus, including dyeing under pressure, as well as for Vigoureux printing or for the preparation of mixtures of dyestuffs.

Given the high concentration desirable, there could be noquestion of obtaining these di-alkali metal salts by diluting by means of suitable non-foaming alkaline subsubstances or by salting out of concentrated solutions of Consequently, only treatment with a caustic alkali of the dyestufi isolatedeither as the free acid or as the monoalkali metal salt, is capable of be mentioned continuous drying on belts, drum dry-- ing, and drying by atomisation.

The following'examples illustrate the invention without restricting it, either from the point of view of the conditions of preparation of the di-alkali metal salts of the monosulphonated di-ortho-hydroxy azo dyestuffs, or

amino-2-naphthol-4-sulphonic acid by operating 'respectively in the presence of copper or zinc salts and, finally, German Patent No. 188,645 has described the preparation of the zinc salt of the dyestuff. It is in this form that the dyestufi has always been prepared up to now by the various dyestufr manufacturing companies, excluding certain products put on the market in the form of the monosodium salt which are not soluble enough to be really interesting to the users.

The progress realised in the field of dyeing, and the development of Vigoureux printing have gradually led the users to work with dyestufis which are diluted as little as possible and having maximum solubility. This has ledto frequent modifications of the conditions of preparation of the dyestufl.

It is known moreover that the dyestuff resulting from the coupling of the diazo compound of 1-amino-2- naphthol-4-sulphonic acid with fi-naphthol, as also that obtained with ot-naphthol, is used in admixture with other metallisable or no-metallisable azo dyestuffs. In many cases, by reason of the very fact that the base dyestuff is a zinc salt, the mixtures obtained have a poor. solubility which necessarily limits their uses.

It has now been found that, quite generally, the dialkali metal salts of monosulphonated di-ortho-hydroxy azo dyestufis, of which the two dyestuffs mentioned above only represent particular cases, otfer an advantage greater than that of the majority of the dyestuffs at present on the market owing to their excellent solubility. 'Ihissolubility allows them to be used for dyeing in apfrom the point of view of the conditions of drying: the. parts indicated are parts by weight.

Example 1 144 parts of ,B-naphthol are dissolved in 275 parts of water at 45 C. by means of 40 parts of .caustic soda. A neutral paste prepared with 272 parts of the mono'sodium salt of the diazo compound of 1-amino-2- naphthol-4-sulphonic acid and 450 parts of water is then.

introduced over a few minutes, while keeping the temperature at 45 C. The 'dyestuif rapidly forms'and the coupling operation is finished in approximately two j hours. dilution and neutralisation until a slightly alkaline reaction is produced, the dyestufi obtained is isolated by filtration.

The paste obtained is gradually added to 100 parts of cold water simultaneously with a solution of 40 parts' i of caustic soda in 100 parts of water, so that fortthe v total addition of dyestufi there corresponds an additionof the chemically equivalent quantity of caustic soda.

As soon as it is homegeneous, the fluid paste so obtained i is dried in an atomiser without special precautions. The

product obtained is in the form of a deep blue powder which gives a pureblue solution with. water; it

sponds to the disodium salt of the dyestufi resulting from the coupling of the diazo compound of l-amino Z-naphthol-4-sulphonic acid with ,B-naphthol.

Example 2 174 parts of 1phenyl-3-methyl-5-pyrazolone are dissolved in 500 parts of water at ordinary temperature with the aid of 40 parts of 100% caustic soda, A

neutral paste prepared with 272 parts of the mono to dye wool, after treatment with dichromate, it enables a bluish red shadeto be -obtained having the same shade and the same properties as that obtained on jusingthe dyestuif prepared according to a conventional method.

I 2,977,354" Patented Mar. 28, 1 961 3 I claim: The process for the'15reparatio'n 'of'a d'ry,stable'dyestufi having the following formula:

References Cited in theme of this patent UNITED STATES PATENTS 778,476 Elbel Dec. 27, 1904 4 Boniger Jan. 9, 1912 Elbel Apr. 16, 1912 Elbel May 14, 1912 Straub et al. Apr. 12, 1927 Straub Mar. 5, 1929 Clingesteinet al. Mar. 26, 1935 Kracker et al. Sept. 24, 1935 Boehmer Feb. 23, 1937 Fleischhauer et al. June 11, 1940 Felix et al. Sept. 11, 1945 Salvin et al. Nov. 13, 1951 Ruegg Aug. 9, 1955 Frisch July 24, 1956 Eberhartet-al. Nov. 5, 1957 Schmid Jan. 7, 1958 FOREIGN PATENTS Great :Britain of 1905 Germany" Dec. 13, 1905 France Aug. 4,1954 

